This video goes over a lot of good information related to pet urine odors and how to remove them. I would add that pet urine is a biological contaminant. It's full of bacteria and damages the surfaces it comes in contact with. Most carpet manufacturers consider pet urine in the carpet as damaged and voids their warranty. As a professional pet odor removal technician in Tampa FL I have some recommendations to add to this video.
Your best bet to remove pet urine in your home is to get to it right away. The sooner you treat it the more likely you will remove the issue before it becomes a much bigger problem. Pet urine becomes a crystal as it dries and becomes very difficult to remove. Rinsing wet urine out of the carpet is the most effective way to handle pet accidents in your home. I recommend pour 2-3 cups of room temperature water on a wet urine spot and then vacuum it up with a small wet dry vacuum. For those of you have a little green machine I recommend using it as a wet dry vacuum without using the cleaning solution or or sprayer on the handle. It just doesn't give you enough solution to wash anything out.
This video mentions using an ozone machine to get rid of pet urine smells in your home. Although, ozone is an effective odor removal tool its not very good at removing embedded odors or odors under layers, like odors in your carpet pad. Ozone machines are not long term solutions and should not be used in an occupied home or office.